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Re: LF: Feeding grounded tower on 136KHz

To: [email protected]
Subject: Re: LF: Feeding grounded tower on 136KHz
From: Rik Strobbe <[email protected]>
Date: Fri, 16 Jul 2004 14:31:53 +0200
In-reply-to: <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
Hello Geoff,

a pity you cannot climb the tower or in any other way get a couple of wire up to the top. Shunt feeding will be very difficult as you will face a impedance of only a few micro-Ohms. So you can expect huge currents (= need of thick wire) and high losses in the matching circuitry. 60m might seem a lot, but it's only 2.7% of the wavelength. So scaled to 160m it's no more than a 4.5m tower or scaled to 20m just a 60cm tower.

73, Rik ON7YD

At 15:02 16/07/2004 +0300, you wrote:
Hello,

New to 136KHz.

Callsigns: ZC4CW or ZC4LOW (for experiments).

I need advice on using a grounded tower as a vertical radiator on 136KHz.
It's approximately 60m high and I can't climb it. This rules out some
of the existing methods which rely on accessing the top of the tower.
Shunt feeding has proven effective on 160m, however can this be done
on 136KHz.  I would be open to other alternatives.

Thankyou,

Geoff







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